DEC M3134-PA DS500 module

Jay West jwest at classiccmp.org
Thu Apr 20 21:05:13 CDT 2006


Richard, if you really need to get an ibm coax term on a pdp, there IS a way 
to do it.

Set the 3270 style terminal to CUT mode instead of DFT. This removes much of 
the "smarts" from the terminal. Hook the 3270 term to a 3174 controller via 
coax. The 3174 controller must have the AEA option installed (ASCII 
emulation). Basically the AEA option gets you a number of serial ports (9 I 
seem to recall) on the back of the 3174 to which you can attach rs232 async 
dumb terminals, or, in your case, run cables to the rs232 async port(s) on a 
"more traditional" host.

Bear in mind you will get a terminal that still won't work right with many 
things you might expect any terminal to work with... for example I don't 
believe any character (full screen) editor would work (and not just because 
of termcap type issues), I don't think TECO would work (esc=$).... etc. But 
you could do it. Most of your application programs (including system 
programs like login, command shell, etc) won't work either because they 
expect character at a time input.

The basic fundamental issue is, in the IBM world what a terminal is/does and 
how a terminal should interact with a host system is a diametrically opposed 
and fundamentally different concept to how one thinks about what a terminal 
is and how it should interact with a host in the async/ascii world. It's 
much much more than just electrical and characterset issues.

So... get a 3174 with option AEA and play around with it and see what you 
think.

Jay West









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